The present application claims priority under 35 USC 119 to Japanese Patent Application No. 2000-391442 filed on Dec. 22, 2000 the entire contents thereof is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a magnetic force type pump driving apparatus for a vehicular engine. More particularly, to an improvement wherein a driving magnet in a ring-like shape is fixedly attached to a driven rotating member which is fixedly attached to one end of a driven shaft of a wrapping transmission apparatus connecting a crank shaft and a driven shaft, a driven magnet concentrically arranged to an inner peripheral side of the driving magnet such that torque can be transmitted to each other, is axially supported rotatably by a pump housing arranged between the two magnets and a pump rotating member is connected to the driven magnet.
2. Description of Background Art
A magnetic type pump driving apparatus is disclosed in, for example, Japanese Patent Laid-Open No. 89069/1998.
The magnetic force type pump driving apparatus as set forth in Japanese Patent Laid-Open No. 89069/1998 discloses a transmission torque between the driving and the driven magnets that is significantly dependent on the diameters of the magnets. However, according to the conventional apparatus, as set forth in Japanese Patent Laid-Open No. 89069/1998, the driving magnet is fixedly attached to an inner peripheral face of a hub having a cylindrical shape of the driven rotating member and accordingly, a large diameter formation of the driving and the driven magnets is restricted by the driven rotating member and it is difficult to achieve an increase in the transmission torque therebetween by the large diameter formation of the driving and the driven magnets.
The invention has been carried out in view of the driving and driven magnets. It is an object thereof to provide a magnetic force type pump driving apparatus in a vehicular engine enabling a large diameter formation of a driving and a driven magnet without being interfered with by the driven rotating member of the wrapping transmission apparatus, capable of achieving an increase in transmission torque and capable of being constituted comparatively compactly.
In order to achieve the above-described object, the invention includes a magnetic force type pump driving apparatus in a vehicular engine in which a driving magnet in a ring-like shape is fixedly attached to a driven rotating member fixedly attached to one end of a driven shaft of a wrapping transmission apparatus for connecting a crank shaft and the driven shaft. A driven magnet is arranged to an inner peripheral side of the driving magnet concentrically to be able to transmit a torque mutually and is axially supported rotatably by a pump housing arranged between the two magnets and a pump rotating member is connected to the driven magnet. A magnet holder crosses a rotational center face of a wrapping member of the wrapping transmission apparatus and is fixedly attached to the driven rotating member. The driving magnet arranged at an outer side of the driven rotating member, is attached to the magnet holder and the driven magnet is axially supported by the pump housing arranged to cross the rotational center face on an inner peripheral side of the driving magnet.
Further, the driven shaft, the wrapping transmission apparatus, the driven rotating member, the wrapping member and the pump rotating member, correspond respectively to a cam shaft 34, a timing controlling transmission apparatus 35, a driven sprocket 37, a timing chain 38 and a pump impeller 48 in an embodiment of the invention, described later.
According to the present invention, the driving magnet arranged at the outer side of the driven rotating member is attached to the magnet holder and therefore, a large diameter formation of the driving and the driven magnets is enabled without being interfered with by the driven rotating member of the wrapping transmission apparatus and an increase in transmission torque of the magnets can be achieved. Further, the magnet holder supporting the driving magnet and the pump housing supporting the driven magnet are arranged such that the magnets cross the rotational center face of the wrapping member and therefore, a space on an inner peripheral side of the driven rotating member, constitutes a space for containing portions of the magnet holder and the pump housing and a total of the pump driving apparatus can be restrained from being enlarged in the axial direction.
Further, the present invention is directed to a driven rotating member that is fixedly attached to an end face of the driven shaft by a plurality of bolts arranged around an axis line of the driven shaft and a boss projecting from an outer side face of the pump housing for axially supporting the driven magnet is made to face a space surrounded by head portions of the bolts.
According to the present invention, the pump housing can be arranged to be as proximate as possible to the driven shaft while avoiding mutual interference between the bolts and the boss and accordingly, space efficiency on the inner peripheral side of the driven rotating member is promoted, which can contribute to compact formation of the pump driving apparatus.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.